add MODERNIZE.md: dependency and idiom cleanup list

Verified dependency reductions (13 unused or replaceable crates) and
idiomatic cleanups for the current codebase. Not applied yet; linked from
ROADMAP phase 0. Toolchain stays on nightly.

MODERNIZE.md

@@ -0,0 +1,122 @@
+# MODERNIZE.md
+
+A list of dependency reductions and idiom cleanups for the current codebase.
+Nothing here is applied yet. Review it, then decide which items to do and when
+(most fit in ROADMAP Phase 0).
+
+Status notes:
+- Every "unused" claim below was verified with a grep: 0 references in `src/`.
+- Toolchain decision: stay on nightly (channel = "nightly"). The stable-Rust
+  item is listed for awareness only.
+- The item 3.2 note about the double `foundry.json` load stays true.
+
+## 1. Delete unused dependencies
+
+Remove these from `Cargo.toml`. None are referenced in `src/`:
+
+| dependency | note |
+|---|---|
+| `itertools` | no usage |
+| `seq-macro` | no usage |
+| `leptos-use` | no usage |
+| `dotenvy` | no usage. Never wired into `main` |
+| `pretty_env_logger` | no usage. Logging uses the `log` macros |
+| `thiserror` | no usage. No error types yet |
+| `http` | optional, enabled by no feature. Code uses `actix_web::http::StatusCode` |
+| `console_log` | no usage. Only `console_error_panic_hook` is called |
+| `anyhow` | only `#[macro_use] extern crate anyhow` and prelude aliases. The `Result` alias and `bail!`/`anyhow!` are used nowhere |
+| `js-sys` | no direct usage. Resolves transitively. Keep the `wasm-bindgen =0.2.126` pin: `hydrate()` uses `#[wasm_bindgen(...)]` |
+
+## 2. Replace crates with std or small local code
+
+1. **`lazy_static` → `std::sync::LazyLock`** (stable since 1.80).
+   Rewrite `src/statics/mod.rs`:
+
+   ```rust
+   use std::sync::LazyLock;
+
+   static ITEMS_REFS: LazyLock<ItemReferenceMap> = LazyLock::new(|| {
+       let mut map = HashMap::with_capacity(5_000);
+       utils::read_items(include_str!("../../data/items.json"), &mut map);
+       // base.json, foundry.json (twice — duplication bug), magic.json
+       info!("Loaded {} items", map.len());
+       ItemReferenceMap(map)
+   });
+
+   static ITEMS_NAMES: LazyLock<Vec<&'static str>> =
+       LazyLock::new(|| ITEMS_REFS.0.keys().map(String::as_str).collect());
+   ```
+
+   Notes:
+   - `include_str!` needs literal paths, so keep the five explicit calls.
+   - The current `HashMap::from_iter(map.into_iter())` roundtrip is a no-op.
+     Wrap the map directly.
+   - `ITEMS_NAMES` changes from `Vec<&'static String>` to `Vec<&'static str>`.
+     The matcher accepts both.
+
+2. **`num-format` → local `group_thousands` helper** in `src/utils/mod.rs`.
+   It exists only for the `ToFormattedString` bound in `Numput`. Drop the
+   bound and render `f.to_string()` grouped. About 6 lines.
+
+3. **`num-traits` → local saturating trait** in `src/components/numput.rs`.
+   It exists only for the `SaturatingAdd`/`SaturatingSub` bounds on `Numput`.
+   Define a small local trait and impl it for `u8`, `u16`, `u32`, `u64`,
+   `usize`. `Numput` keeps its generics.
+
+4. **`serde` (direct) → remove now, re-add in ROADMAP phase 1.**
+   No derives exist today; `serde_json::Value` works without naming `serde`
+   in `Cargo.toml`. Phase 1 (persistence) re-adds
+   `serde = { version = "1", features = ["derive"] }`.
+
+Result: `[dependencies]` drops from 27 entries to about 13.
+
+## 3. Idiomatic cleanups (no dependency changes)
+
+1. Delete `#![feature(type_alias_impl_trait)]` in `src/lib.rs:6`.
+   It is unused and warns.
+
+2. Stay on nightly. The code uses only stable features (let-chains, let-else,
+   edition 2024, `LazyLock`). If the toolchain is ever revisited: drop the
+   `nightly` features from `leptos`/`leptos_router`, install stable, and run
+   the three checks. The original build breakage was a nightly regression
+   (`min_adt_const_params` re-gating in nightly 1.99); stable does not have
+   that class of failure.
+
+3. Prelude (`src/prelude.rs`):
+   - Remove the blanket `#![allow(unused_imports)]` and
+     `#![allow(dead_code)]`. They hide real warnings.
+   - Remove the single-letter `log` aliases
+     (`warn as w, log as l, info as i, ...`). They are unused.
+   - Remove the `anyhow` re-exports and typealiases.
+   - Replace legacy `#[macro_use] extern crate log;` in `src/lib.rs` with
+     `use log::{info, error};` at the two call sites.
+
+4. `read_items` (`src/utils/mod.rs`): use the `Entry` API instead of
+   `contains_key` → `get_mut().unwrap()`. Removes the unwrap and the double
+   lookup.
+
+5. Mock data (`src/entities/mock.rs`):
+   `HashSet::from_iter(vec![...])` → `HashSet::from([...])`.
+   The date `unwrap`s are fine: the data is static.
+
+6. Minor: `adjust_checked` drops `-> ()`; `numput.rs` drops the unused
+   `leptos::{ logging, ... }` import.
+
+## 4. Opinionated (do only on request)
+
+1. `chrono` → `jiff`. Nicer API, actively maintained. Not worth the churn
+   for this model. If kept: `chrono`'s `serde` feature is unused today —
+   trim it now, re-add in phase 1.
+2. `cargo fmt` normalization. The repo uses `fn foo (` spacing; it may be
+   deliberate. Ask before running.
+3. Clippy pass over the result.
+
+## Verification
+
+After applying items 1-3, run:
+
+```
+cargo check --no-default-features --features hydrate --lib
+cargo check --no-default-features --features ssr --bin aex
+cargo check --target wasm32-unknown-unknown --no-default-features --features hydrate --lib
+```

ROADMAP.md

@@ -58,6 +58,8 @@ Cheap, unblocks the rest. Can happen any time; do it first.
 - [ ] deduplicate `foundry.json` load in `src/statics/mod.rs` (loaded twice)
 - [ ] clear compiler warnings (unused imports, unused `qty` in `item.rs`)
 - [ ] decide Cargo.lock policy — currently gitignored, builds are non-reproducible; commit it
+- [ ] dependency and idiom cleanup — see `MODERNIZE.md` (drop unused deps,
+      `lazy_static` → `LazyLock`, local replacements for `num-format`/`num-traits`)
 - [ ] drop unused dependencies (`leptos-use`, `dotenvy`, `pretty_env_logger` if confirmed unused)
 - [ ] replace `end2end/tests/example.spec.ts` with a smoke test (app boots, nav renders, no console errors)